A Collection of Useful Classes - Beginning Java - page 712

they were. You can reset all fields for a GregorianCalendar object to undefined by calling its clear()
method.
The other versions of the set() method are:
set(int year, int month, int day, int hour, int minute)
set(int year, int month, int day, int hour, int minute, int second)
set(int field, int value)

It's obvious what the first two of these do. In each case the fields not explicitly set are left at their original
values. The third version of set() sets a field specified by one of the integer constants defined in the Cal-
endar class for this purpose (shown in Table 15-2 ) :

TABLE 15-2 : Calendar Field Setting Options
FIELD VALUE
AM_PM Can have the values AM or PM , which correspond to values of 0 and 1
DAY_OF_WEEK Can have the values SUNDAY , MONDAY , and so on, through to SATURDAY , which correspond to
values of 1 to 7
DAY_OF_WEEK_IN_MONTH Ordinal number for the day of the week in the current month.
DAY_OF_YEAR Can be set to a value from 1 to 366
MONTH Can be set to a value of JANUARY , FEBRUARY , and so on, through to DECEMBER , corresponding
to values of 0 to 11
DAY_OF_MONTH or DATE Can be set to a value from 1 to 31
WEEK_OF_MONTH Can be set to a value from 1 to 6

Can be set to a value from 1 to 54 WEEK_OF_YEAR

A value from 0 to 23 HOUR_OF_DAY

A value from 1 to 12 representing the current hour in the a.m. or p.m. HOUR

The current minute in the current hour — a value from 0 to 59 MINUTE

The second in the current minute, 0 to 59 SECOND

The millisecond in the current second, 0 to 999 MILLISECOND

The current year — for example, 2011

YEAR

Can be set to either GregorianCalendar.BC or GregorianCalendar.AD (both values being
defined in the GregorianCalendar class)

ERA

A millisecond value indicating the offset from GMT ZONE_OFFSET

A millisecond value indicating the offset for daylight saving time in the current time zone DST_OFFSET

Qualifying the names of these constants with the class name GregorianCalendar can make the code
look cumbersome but you can use static import for the constants to simplify things:
import static java.util.Calendar.*;
import static java.util.GregorianCalendar.*;

The static import statement imports only the names of static data members that are defined in a class,
not the names of inherited members. Therefore, you need two import statements if you want access to all
the constants you can use with the GregorianCalendar class.
With these two import statements in effect, you can write statements like this:
GregorianCalendar calendar = new GregorianCalendar();
calendar.set(DAY_OF_WEEK, TUESDAY);